Soak mushrooms in water for 2-3 hours, then boil them in the same water (they are ready when they drown on the bottom). Wash them by running water. Cut mushrooms in strips and fry in oil. Strain mushroom water through 3-4 layers of gauze. Chop sauerkraut finely, stew with a little sugar, 1/2 tbsp oil, 3 tbsp water on average heat until it is soft and tender. Chop all other vegetables and roots finely and fry in oil. Put sauerkraut, mushrooms and fried vegetables in mushroom water. Fry flour on dry pan until it is golden. Pour in a little water and having stirred thoroughly, add to schi. Season schi on your taste. You can use potatoes, but don't add flour then. Serve with chopped greens.